CN107807439B

CN107807439B - Interchangeable of dolly-out,ing dolly-back tight shot

Info

Publication number: CN107807439B
Application number: CN201711195154.0A
Authority: CN
Inventors: 尚洁阳; 诸益炜; 徐雄飞; 盛亚茗; 张平华
Original assignee: Jiaxing Zhongrun Optical Technology Co Ltd
Current assignee: Jiaxing Zhongrun Optical Technology Co Ltd
Priority date: 2017-11-24
Filing date: 2017-11-24
Publication date: 2019-03-08
Anticipated expiration: 2037-11-24
Also published as: CN107807439A

Abstract

One kind is dolly-out,ed dolly-back interchangeable tight shot, it include: the first eyeglass group, diaphragm and the second eyeglass group for focusing and correcting aberration of the field angle for being used to converge light and forming demand set gradually from the object side to image side, in which: the first eyeglass group includes: the first eyeglass with positive light coke, the second eyeglass with positive light coke, the third eyeglass with positive light coke, the 4th eyeglass with negative power；Second eyeglass group includes: the 5th eyeglass with negative power, the 6th lens with positive light coke, with the cemented doublet of positive light coke, i.e. the 8th eyeglass；Diaphragm and the spacing of the second eyeglass group are fixed, so that composition can be along the zoom group that optical axis moves forward and backward.When shooting object from infinity to when short distance variation, the first eyeglass group is fixed, and diaphragm and the second eyeglass group entirety are focused from image space to object space movement.The present apparatus meets the 8k resolution ratio of matching silent frame and super35 picture film camera, and camera lens whole process in changing object distance focussing process distorts without dark angle, and under each object distance, and small, cell breath is faint, while having superelevation cost performance and machinability.

Description

Interchangeable of dolly-out,ing dolly-back tight shot

Technical field

The present invention relates to a kind of technology in optical device field, specifically a kind of interchangeable tight shot of dolly-out,ing dolly-back.

Background technique

The film camera of profession generally requires 5-6 interchangeable lens of collocation, and commutative with cinema scene is specifically for shadow Piece shooting environmental is made to measure, not only needs to match the size sensor of silent frame, with greater need for resolution ratio, optical aberration, Cell breath etc. combines the physical condition of shooting video to comprehensively consider, while in terms of weight and cost being also required to plan as a whole simultaneous It cares for.The major defect of camera lens includes: the video camera use that resolving power can not match up to 6k 8k resolution ratio at present at present；Institute There is camera lens more or less can all have dark angle, is unable to satisfy video and film shooting uses；Camera lens is often inadequate to the control of distortion, So being unable to satisfy cinema scene to the high request of distortion；During camera lens is focused, internal lens set can occur one The displacement of consecutive focuses on the incident light of specific range on imaging surface.When moving burnt between multiple focuses, inside camera lens The displacement of lens set may slightly change picture visual field size, it appears that just as slightly zoom, that is, there is breathing effect It answers.

Summary of the invention

The present invention In view of the above shortcomings of the prior art, proposes that one kind is dolly-out,ed dolly-back interchangeable tight shot, meets 8k resolution ratio with silent frame and super35 picture film camera, camera lens change object distance focussing process in whole process without dark angle, and And distort that small, cell breath is faint under each object distance, while there is superelevation cost performance and machinability.

The present invention is achieved by the following technical solutions:

The present invention includes: the first of the field angle for being used to converge light and forming demand set gradually from the object side to image side Eyeglass group, diaphragm and the second eyeglass group for focusing and correcting aberration, in which: the first eyeglass group includes: with positive light coke The first eyeglass, the second eyeglass with positive light coke, the third eyeglass with positive light coke, the 4th mirror with negative power Piece；Second eyeglass group includes: the 5th eyeglass with negative power, the 6th lens with positive light coke, has positive light coke Cemented doublet, i.e. the 8th eyeglass；Diaphragm and the spacing of the second eyeglass group are fixed, thus what composition can be moved forward and backward along optical axis Zoom group.When shooting object from infinity to when short distance variation, the first eyeglass group is fixed, and diaphragm and the second eyeglass group are whole Body is focused from image space to object space movement.

The first eyeglass group is positive light coke.

The second eyeglass group is positive light coke, and the 5th to the 8th eyeglass therein is preferably aspherical lens, is used for Further promote image quality.

6th lens have the eyeglass of positive light coke using the lens combination or monolithic of two panels positive light coke, wherein Monolithic eyeglass can dramatically increase symmetry and have smaller distortion.

Technical effect

Compared with prior art, the technology of the present invention effect includes:

1) matched sensors are difficult to solve the problems, such as that existing camera lens resolution ratio is too low, the present invention is added in camera lens Glass aspheric eyeglass, has been obviously improved resolving power and resolution ratio, enables the invention to meet at present best result on the market The use of the professional 8K resolution camera of resolution.

2) big to solve the problems, such as that existing camera lens distort, present invention optimizes the structure of camera lens and optical paths, make diaphragm Eyeglass two group in front and back has symmetry about diaphragm as far as possible, so that distortion is minimum, TV distortion is 2% hereinafter, ensure that picture It is not in deformation and distortion situation from center to periphery.

3) to solve the problems, such as that camera lens surrounding brightness is too low to dark angle occur, the present invention uses and biography in design The angle of incidence of light design that sensor matches, improves periphery light ratio.Even if when aperture standard-sized sheet, periphery light ratio 40% or more, make to present on picture more evenly by the light of entire camera lens, without dark angle in full object distance range.

4) to solve the problems, such as that existing camera lens cell breath is obvious, the present invention is moved integrally using the subsequent group of diaphragm The mode of focusing.When shooting object from infinity to when short distance variation, pre-group is fixed, and diaphragm and rear group are together from image space It is focused to object space overall movement.Particularly, diaphragm is in optimal position at a distance from forward and backward eyeglass during refocusing It sets, has accomplished camera lens from when infinitely focusing as far as minimum distance, picture field angle changes within 3%, effectively weakens camera lens and exists Cell breath in focussing process.

Detailed description of the invention

Fig. 1 is 1 structural schematic diagram of embodiment；

Fig. 2 is spherical aberration, the curvature of field, distortion figure of 1 camera lens of embodiment relative to d line；

Fig. 3 is coma figure of 1 camera lens of embodiment relative to d line；

Fig. 4 is 2 structural schematic diagram of embodiment；

Fig. 5 is spherical aberration, the curvature of field, distortion figure of 2 camera lens of embodiment relative to d line；

Fig. 6 is coma figure of 2 camera lens of embodiment relative to d line；

In figure: the first eyeglass group G1, diaphragm S, the second eyeglass group G2, the first eyeglass L1, the second eyeglass L2, third eyeglass It is L3, the 4th eyeglass L4, the 5th eyeglass L5, the 6th eyeglass L6, the 7th eyeglass L7, the 8th eyeglass L8, nearly object space side mirror piece L81, close Image side eyeglass L82, image planes IMG.

Specific embodiment

Embodiment 1

As shown in Figure 1, the present embodiment includes: to be set gradually from the object side to image side for converging light and forming demand The first eyeglass group G1, the diaphragm S of field angle and the second eyeglass group G2 for focusing and correcting aberration, in which: the first eyeglass group G1 includes: the first eyeglass L1, the second eyeglass L2 with positive light coke, the third with positive light coke with positive light coke Eyeglass L3, the 4th eyeglass L4 with negative power；Second eyeglass group G2 include: the 5th eyeglass L5 with negative power, with And including there are the 6th lens of the 6th eyeglass L6 of positive light coke and the 7th eyeglass L7 with positive light coke, there is positive light focus The cemented doublet of degree, i.e. the 8th eyeglass L8；Diaphragm S and the spacing of the second eyeglass group G2 are fixed, so that composition can be before optical axis The zoom group moved afterwards.When shoot object from infinity to short distance change when, the first eyeglass group G1 is fixed, diaphragm S and Second eyeglass group G2 is whole to be focused from image space to object space movement.

The first eyeglass group G1 is positive light coke.

The second eyeglass group G2 is positive light coke, and the 5th to the 8th eyeglass therein is preferably aspherical lens, is used In further promotion image quality.

The spacing of the 4th lens posterior surface center to diaphragm meets (10 mm, 40 mm)；5th eyeglass The spacing of front surface center to diaphragm meets (3.5 mm, 7.5mm), so that camera lens object distance is from infinitely as far as the mistake of short distance change The field angle variation of Cheng Zhong, camera lens are small.If being lower than the lower limit of the conditional, it will lead to lens aperture diameter and entire outer diameter increase Greatly, difficulty promotion is made；If being higher than the upper limit of the conditional, during will lead to lens focusing, field angle variation is excessive, exhales It is obvious to inhale effect.

The spacing of the 4th lens posterior surface center to diaphragm meets (13.21mm, 37.15mm) in the present embodiment；5th mirror The spacing of piece front surface center to diaphragm is 5.50.

The optic back focal of the interchangeable tight shot of dolly-out,ing dolly-back and the ratio of whole focal length meet (0.3,0.7), make The focal length and rear burnt ratio for obtaining camera lens are in a suitable range.If being lower than the lower limit of the conditional, camera lens will lead to Rear coke it is too short, it is difficult to match film camera on the market, reduce the versatility of camera lens；If being higher than the upper of the conditional Limit, then it is too long to will lead to rear lens focus, from it is infinite focus as far as short distance when, the whole spherical aberration and coma mistake of the second eyeglass group G2 Greatly, image quality declines.

The focal distance ratio of the first eyeglass group G1 and the second eyeglass group G2 meets (1.7,2.5), if being lower than the conditional Lower limit, then it is excessive to will lead to camera lens the first eyeglass group's G1 optical power profile, and then cause second eyeglass group's G2 focal power too low, So that the eyeglass bore of the second eyeglass group G2 increases, overall weight increases, and cost is excessively high；If being higher than the upper limit of the conditional, Cause camera lens the first eyeglass group's G1 light focus to be spent weak, so that camera lens front end eyeglass bore is excessive, also results in camera lens overall weight Increase, is unfavorable for the miniaturization of camera lens, is also unfavorable for the assembly of camera lens and the adjustment of overall weight and center of gravity.

The focal length of the first eyeglass group G1 and the second eyeglass group G2 are respectively 251.1mm and 113.5mm, ratio in the present embodiment Value is 2.21.

The specific refractivity of the refractive index of nearly object space side mirror piece L81 and nearly image side eyeglass L82 in 8th eyeglass Meet (0.2,0.5), if being lower than the lower limit of the conditional, the refractive index of balsaming lens is little, is unfavorable for correcting camera lens Axial chromatic aberration and ratio chromatism, while be difficult to compensate for the first eyeglass group G1 formation spherical aberration；If being higher than the conditional The upper limit, then the reflectivity that will lead between cemented surface is too strong, causes the ghost of camera lens serious；It will lead to the first eyeglass group G1 simultaneously The spherical aberration correction of formation is excessive, reduces lens performance.

In the present embodiment in the 8th eyeglass the refractive index of nearly object space side mirror piece L81 and nearly image side eyeglass L82 refractive index Respectively 1.52 and 1.80, absolute value of the difference 0.28.

Preferably, the lens parameters in the present embodiment are specific as follows:

The EFL=135.0 of the present embodiment, BFL=56.58mm~80.52mm, (TNO is that camera lens calculates transmission to TNO=2.0 F-number after rate).The optic back focal of interchangeable of dolly-out,ing dolly-back in the present embodiment tight shot and the ratio of whole focal length are 0.42 ~0.59.

Table 1

1 lens construction parameter of embodiment

Surface serial number	Surface type	Radius of curvature	Thickness/distance	Refractive index	Abbe number
						Object plane			Z0
S1	Spherical surface	61.38	8.24	1.88	35.6
						S2	Spherical surface	104.47	1.07
S3	Spherical surface	68.21	9.23	1.50	70.2
						S4	Spherical surface	269.53	0.68
S5	Spherical surface	47.40	8.76	1.62	63.2
						S6	Spherical surface	70.97	3.04
S7	Spherical surface	159.10	4.11	1.80	25.6
						S8	Spherical surface	33.10	Z1
Diaphragm	Plane	INF	5.50
						S10	Spherical surface	-46.65	3.21	1.70	30.2
S11	Spherical surface	170.33	1.43
						S12	Spherical surface	936.27	4.97	1.90	37.5
S13	Spherical surface	-65.26	0.90
						S14	It is aspherical	111.46	3.60	1.83	42.7
S15	It is aspherical	967.74	11.21
						S16	Spherical surface	-68.41	4.01	1.52	68.4
S17	Spherical surface	INF	4.78	1.80	41.3
						S18	Spherical surface	-65.90	Z2
Image planes			-

Table 2

From D0 to D1 change process, as object distance from it is infinite as far as nearest photo distance change process.FOV is camera lens Diagonal field of view angle, from D0 to D1 change when, FOV has only changed 2.4%, and cell breath is faint.

In order to improve whole image quality, the curvature of field and distortion are further eliminated, the 7th eyeglass (L7) is arranged to Aspherical, coefficient is as shown in table 3.

Table 3

Camera lens asphericity coefficient

The aspherical formula are as follows:

Wherein: when Z is the position that the aspherical height along optical axis direction is h, away from aspheric vertex of surface apart from rise sag；C=1/ R, R indicate the radius of curvature of mirror surface, and K is circular cone coefficient conic, and A, B, C, D, E, F are high order aspheric surface coefficient, and in coefficient E represent scientific count number, example e-005 indicates 10^-5。

Embodiment 2

Compared with Example 1, the 6th lens are realized using monolithic with the eyeglass of positive light coke in the present embodiment, i.e., the 6th Eyeglass L6, and the spacing of the 4th lens posterior surface center to diaphragm meets (15.77mm, 34.26mm) in the present embodiment；The The spacing of five lens front surface centers to diaphragm is 6.23.

The focal length of the first eyeglass group G1 and the second eyeglass group G2 are respectively 169.6mm and 91.3mm, ratio in the present embodiment Value is 1.85.

In the present embodiment in the 8th eyeglass the refractive index of nearly object space side mirror piece L81 and nearly image side eyeglass L82 refractive index Respectively 1.48 and 1.75, absolute value of the difference 0.27.

The EFL=135.0mm of the present embodiment camera lens, BFL=62.11mm~80.60mm, (TNO is camera lens meter to TNO=2.2 F-number after calculating transmitance).The optic back focal of interchangeable of dolly-out,ing dolly-back in the present embodiment tight shot and the ratio of whole focal length It is 0.46~0.60.

The first eyeglass group and the second eyeglass group of the present embodiment are higher about diaphragm symmetry, therefore compared to embodiment 1, With smaller optical distortion.But the present embodiment does not use aspherical, therefore as can be seen from Figure 5 spherical aberration and the curvature of field be all Expanded compared to embodiment 1.

Table 4

Lens construction parameter

Surface serial number	Surface type	Radius of curvature	Thickness/distance	Refractive index	Abbe number
						Object plane			Z0
s1	Spherical surface	63.48	8.43	1.92	31.3
						s2	Spherical surface	108.48	0.88
s3	Spherical surface	70.41	9.34	1.61	84.6
						s4	Spherical surface	270.43	0.51
s5	Spherical surface	50.18	8.12	1.75	61.4
						s6	Spherical surface	74.65	2.97
s7	Spherical surface	163.74	3.92	1.81	35.4
						s8	Spherical surface	32.59	Z1
Diaphragm	Plane	INF	6.23
						s10	Spherical surface	-42.94	3.14	1.59	30.5
s11	Spherical surface	171.79	1.29
						s12	Spherical surface	936.36	5.64	1.91	35.3
s13	Spherical surface	-61.32	1.72
						s14	Spherical surface	-68.39	3.61	1.48	74.4
s15	Spherical surface	inf	4.99	1.75	48.5
						s16	Spherical surface	-64.10	Z2
Image planes

Table 5

	POS1	POS2
			Z0	INF	815
Z1	34.26	15.77
			Z2	62.11	80.60
FOV	18.94	18.52

From D0 to D1 change process, as object distance from it is infinite as far as nearest photo distance change process.FOV is camera lens Diagonal field of view angle, from D0 to D1 change when, FOV has only changed 2.3%, and cell breath is faint.

Above-mentioned specific implementation can by those skilled in the art under the premise of without departing substantially from the principle of the invention and objective with difference Mode carry out local directed complete set to it, protection scope of the present invention is subject to claims and not by above-mentioned specific implementation institute Limit, each implementation within its scope is by the constraint of the present invention.

Claims

The interchangeable tight shot 1. one kind is dolly-out,ed dolly-back characterized by comprising what is set gradually from the object side to image side is used to converge Light and formed demand field angle the first eyeglass group, diaphragm and the second eyeglass group for focusing and correcting aberration, in which:

First eyeglass group includes: the first eyeglass with positive light coke, the second eyeglass with positive light coke, has positive light coke Third eyeglass, the 4th eyeglass with negative power；

Second eyeglass group includes: the 5th eyeglass with negative power, the 6th lens with positive light coke, has positive light coke The 8th eyeglass；Diaphragm and the spacing of the second eyeglass group are fixed, so that composition can be along the zoom group that optical axis moves forward and backward；Work as bat When taking the photograph object and changing from infinity to short distance, the first eyeglass group is fixed, diaphragm and the second eyeglass group it is whole from image space to Object space movement is focused；

6th lens are sixth eyeglass of the monolithic with positive light coke or the 6th eyeglass with positive light coke and have The combination of 7th eyeglass of positive light coke；

The first eyeglass group is positive light coke；The second eyeglass group is positive light coke, the 5th eyeglass therein to the Eight eyeglasses are aspherical lens；

The spacing of the 4th lens posterior surface center to diaphragm meets (10 mm, 40 mm)；Table before 5th eyeglass The spacing of face center to diaphragm meets (3.5 mm, 7.5mm)；

The optic back focal of the interchangeable tight shot of dolly-out,ing dolly-back and the ratio of whole focal length meet (0.3,0.7)；

The focal distance ratio of the first eyeglass group and the second eyeglass group meets (1.7,2.5)；

8th eyeglass is cemented doublet, the refractive index of nearly object space side mirror piece and nearly image side eyeglass in the cemented doublet Specific refractivity meets (0.2,0.5).
2. interchangeable tight shot according to claim 1 of dolly-out,ing dolly-back, characterized in that the 7th eyeglass is aspheric Face eyeglass, aspherical formula are as follows:, Wherein: when Z is the position that the aspherical height along optical axis direction is h, away from aspheric vertex of surface apart from rise sag；, R indicates the radius of curvature of mirror surface, and K is circular cone coefficient conic, and A, B, C, D, E, F are high order aspheric surface coefficient.
3. interchangeable tight shot according to claim 1 of dolly-out,ing dolly-back, characterized in that

The object side of first eyeglass is spherical surface, radius of curvature 61.38, the first eyeglass with a thickness of 8.24, refractive index 1.88, Abbe number is 35.6;The image side surface of first eyeglass is spherical surface, radius of curvature 104.47, the image side surface of the first eyeglass to the second mirror The distance of the object side of piece is 1.07;

The object side of second eyeglass is spherical surface, radius of curvature 68.21, the second eyeglass with a thickness of 9.23, refractive index 1.5, Abbe number is 70.2;The image side surface of second eyeglass is spherical surface, radius of curvature 269.53, the image side surface of the second eyeglass to third mirror The distance of the object side of piece is 0.68;

The object side of third eyeglass is spherical surface, radius of curvature 47.4, third eyeglass with a thickness of 8.76, refractive index 1.62, Abbe number is 63.2;The image side surface of third eyeglass is spherical surface, radius of curvature 70.97, the image side surface of third eyeglass to the 4th mirror The distance of the object side of piece is 3.04;

The object side of 4th eyeglass is spherical surface, radius of curvature 159.1, the 4th eyeglass with a thickness of 4.11, refractive index 1.8, Abbe number is 25.6;The image side surface of 4th eyeglass is spherical surface, radius of curvature 33.1, the image side surface of the 4th eyeglass to diaphragm away from From being 37.15 ~ 13.21；

Diaphragm is plane, and the distance of diaphragm to the object side of the 5th eyeglass is 5.5;

The object side of 5th eyeglass is spherical surface, and radius of curvature is -46.65, the 5th eyeglass with a thickness of 3.21, refractive index 1.7, Abbe number is 30.2;The image side surface of 5th eyeglass is spherical surface, radius of curvature 170.33, the image side surface of the 5th eyeglass to the 6th mirror The distance of the object side of piece is 1.43;

The object side of 6th eyeglass is spherical surface, radius of curvature 936.27, the 6th eyeglass with a thickness of 4.97, refractive index 1.9, Abbe number is 37.5;The image side surface of 6th eyeglass is spherical surface, and radius of curvature is -65.26, the image side surface of the 6th eyeglass to the 7th mirror The distance of the object side of piece is 0.9;

The object side of 7th eyeglass is aspherical, radius of curvature 111.46, the 7th eyeglass with a thickness of 3.6, refractive index is 1.83, Abbe number 42.7;The image side surface of 7th eyeglass is aspherical, radius of curvature 967.74, the image side surface of the 7th eyeglass Distance to the object side of the 8th eyeglass is 11.21;

The object side circular cone coefficient of 7th eyeglass is 0, and the circular cone coefficient of the image side surface of the 7th eyeglass is 0;The object side of 7th eyeglass Face quadravalence asphericity coefficient is -2.16E-03, and the quadravalence asphericity coefficient of the image side surface of the 7th eyeglass is 2.86E-07;7th mirror The six rank asphericity coefficient of object side of piece is -4.03E-06, and six rank asphericity coefficients of the image side surface of the 7th eyeglass are 6.28E- 06;The eight rank asphericity coefficient of object side of 7th eyeglass is 5.26E-07, eight rank asphericity coefficients of the image side surface of the 7th eyeglass For 2.55E-06;The ten rank asphericity coefficient of object side of 7th eyeglass is -3.12E-05, and ten ranks of the image side surface of the 7th eyeglass are non- Asphere coefficient is -4.17E-08;

The object side of the nearly object space side mirror piece of 8th eyeglass is spherical surface, and radius of curvature is -68.41, the nearly object space side of the 8th eyeglass Eyeglass with a thickness of 4.01, refractive index 1.52, Abbe number 68.4;

The image side surface of the nearly object space side mirror piece of 8th eyeglass is plane, the nearly image side eyeglass of the 8th eyeglass with a thickness of 4.78, Refractive index is 1.8, Abbe number 41.3;

The image side surface of the nearly image side eyeglass of 8th eyeglass is spherical surface, and radius of curvature is -65.9.
4. interchangeable tight shot according to claim 1 of dolly-out,ing dolly-back, characterized in that

The object side of first eyeglass is spherical surface, radius of curvature 63.48, the first eyeglass with a thickness of 8.43, refractive index 1.92, Abbe number is 31.3;The image side surface of first eyeglass is spherical surface, radius of curvature 108.48, the image side surface of the first eyeglass to the second mirror The distance of the object side of piece is 0.88;

The object side of second eyeglass is spherical surface, radius of curvature 70.41, the second eyeglass with a thickness of 9.34, refractive index 1.61, Abbe number is 84.6;The image side surface of second eyeglass is spherical surface, radius of curvature 270.43, the image side surface of the second eyeglass to third mirror The distance of the object side of piece is 0.51;

The object side of third eyeglass is spherical surface, radius of curvature 50.18, third eyeglass with a thickness of 8.12, refractive index 1.75, Abbe number is 61.4;The image side surface of third eyeglass is spherical surface, radius of curvature 74.65, the image side surface of third eyeglass to the 4th mirror The distance of the object side of piece is 2.97;

The object side of 4th eyeglass is spherical surface, radius of curvature 163.74, the 4th eyeglass with a thickness of 3.92, refractive index is 1.81, Abbe number 35.4;The image side surface of 4th eyeglass is spherical surface, radius of curvature 32.59, the image side surface of the 4th eyeglass to light The distance of door screen is 34.26 ~ 15.77;

Diaphragm is plane, and the distance of diaphragm to the object side of the 5th eyeglass is 6.23;

The object side of 5th eyeglass is spherical surface, and radius of curvature is -42.94, the 5th eyeglass with a thickness of 3.14, refractive index is 1.59, Abbe number 30.5;The image side surface of 5th eyeglass is spherical surface, and radius of curvature 171.79, the image side surface of the 5th eyeglass is extremely The distance of the object side of 6th eyeglass is 1.29;

The object side of 6th eyeglass is spherical surface, radius of curvature 936.36, the 6th eyeglass with a thickness of 5.64, refractive index is 1.91, Abbe number 35.3;The image side surface of 6th eyeglass is spherical surface, and radius of curvature is -61.32, and the image side surface of the 6th eyeglass is extremely The distance of the nearly object space of 8th eyeglass is 1.72;

The object side of the nearly object space side mirror piece of 8th eyeglass is spherical surface, and radius of curvature is -68.39, the nearly object space side of the 8th eyeglass Eyeglass with a thickness of 3.61, refractive index 1.48, Abbe number 74.4;

The image side facial plane of the nearly object space side mirror piece of 8th eyeglass, the nearly object space side mirror piece of the 8th eyeglass with a thickness of 4.99, folding Penetrating rate is 1.75, Abbe number 48.5;

The image side surface of the nearly image side eyeglass of 8th eyeglass is spherical surface, and radius of curvature is -64.1.